Definition of Term: Space filling design

Several toolkit operations call for a set of points to be specified in the simulator space of inputs, and the choice of such a set is called a design. Space-filling designs are a class of a simple general purpose designs giving sets of points, or training samples at which the simulator is run to provide data to build the emulator. They spread points in an approximately uniform way over the design space. They could be any design of the following types.

• a design based on restricted sampling methods.
• a design based on measures of distance between points.
• a design known to have low “discrepancy” interpreted as a formal measure of the closeness to uniformity.
• a design that is a hybrid of, or variation on, these designs.